Refrigerator control



Nov. 7, 1933. J. J. BAUMAN 7 REFRIGERATOR CONTROL Filed June 17. 1932 2 Sheets-Sheet 1 I 11v VEIIVTOR B Y J a BHUMHM OVI G93 M ATTORNEY Nov. 7, 1933. J. J. BAUMAN REFRIGERATOR CONTROL Filed June 17, 1932 2 Sheets-Sheet 2 F'xa. 4

INVENTOR J J BRUMHN.

a, q A TTORNEY' Patented Nov. 7, 1933 I UNITED STATES 1,934,607 narmcaaa'ron common John J. Bauman, Springfield, Mama, assignor to Westinghouse Electric 8; Manufacturing Company, East Pittsburgh, Pa.,

. Pennsylvania a corporation of Application June 17, 1032. Serial No. 617,909

12 Claims. (Cl- 200-140) in household types,'it is desirable to maintain cooling unit or heat absorbing unit of the refrig normally a predetermined mean temperature therein.

For example, if it is desired to maintain the crating system at a mean temperature of 9 F., the control mechanism should be capable of automatically starting the operation of the refrigerating-system whenever the cooling unit reaches a temperature of, for example, 15 F., and of stopping the operation of the system whenever the temperature of the cooling unit is reduced to,

for example, 3 F. It is also desirable to be able to change this predetermined mean temperature at will and to operate the refrigerator periodi- ,cally at a temperature sufficiently high to defrost portions of the system. In other words, to maintain the cooling or heat absorbing unit at a mean temperature which is sufficiently high to melt frost off the cooling unit which has accumulated thereon during operation at relatively lower mean temperature. These advantages are obtained by my novel control mechanism when applied to refrigerators having a cabinet compartment and a machine for producing refrigeration therein.

In practicing my invention, 1 provide an electric switch for controlling the operation of the machine and a thermostatic element for actuating the switch in response to the cabinet compartment temperatures, whereby the compartment is maintained between predetermined high and low temperatures. Adjustments are provided on the control mechanism for changing these pre-. determined temperatures, which changes are made without the use of a complicated system of springs or other biasing devices. One of the temperature adjustments is readily accessible to the operator and changes the mean temperature to be maintained within the cabinet, the cabinet temperature being responsive to the temperature of the heat absorbing or cooling unit, as is well understood in the art. This adjustment has a plurality of positions corresponding to various mean cabinet and cooling unit temperatures and preferablyhas a position where the temperatures maintained within the cabinet and in the cooling unit are sumciently high to defrost portions of the system such as, for example, the

sired temperature. nism is used to control a mechanically operated evaporatonwith continuance of cycling to maintain a mean temperature'or temperature range high enough to provide defrosting but low enough to prevent rapid food spoilage.

More particularly, my invention comprises a temperature control mechanism embodying a switch opened and closed by a rockable or tiltable member, the latter being operated by a member or lever movable in response to thermal conditions, together with means for advancing or retarding tilting or rocking of the tlltable or rockable member with respect to the operating range of movement of the movable member or lever. The movable member or lever is moved in one direction by biasing means, for example, a spring, and in the other direction by means, such as a bellows, responsive to temperature. The biasing means or spring may be adjusted to regulate the general desired setting of the mechanism, and further regulation may be secured by the advancing and retarding means to raise or lower the de- When the control mecharefrigerator, adjustment of the advancing and retarding means in the advance direction lowers the temperatures at which the switch is closed to secure operation and at which the switch is opened to interrupt operation, and adjustment in the retard direction has the contrary effect. By adjustment in this way of the temperatures at which the switch is closed and opened, it is possible' to have a refrigerator operated at such a high temperature range that defrosting of the evaporator and associated elements may be effected with cycling thereof, whereby, during defrosting, the attainable upper temperature will be limited and food spoilage minimized. I also provide means for limiting motion of the temperature responsive movable member or lever so that, with the advancing and retarding adjustment means in full retarded position, closing of the switch is prevented, this being useful ineffecting rapid defrosting; and also, I preferably provide means for limiting motion of the temperature responsive movable member or lever sothat, with the advancing and retarding adjustment means in full advance position, opening of the switch is prevented, this being useful in eflecting rapid freezing or cooling.

It is another object of my invention'to provide a control mechanism for a mechanical refrigerator capable of regulationto obtain defrosting with maintenance of-cyclic operation.

It is a further object of the invention to provide a temperature control mechanism having adlusting means for advancing and retarding opening and closing of a switch relative to movement of the temperature responsive means.

It is a still further object of my invention to provide a. temperature control mechanism for a refrigerator having a series of adjusted positions for cycling the machine to maintain progressively increasing temperatures within the refrigerator, the highest of which is effective todefrost the evaporator of the refrigerator.

It is a further object of my invention to provide a mechanical or electrical refrigerator with control mechanism capable of being adjusted to interrupt operation or to maintain continuous operation, or both.

These and other objects are effected by my invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. l is a view of a refrigerator having my control mechanism applied thereto;

Fig.2 is a front elevation of my novel control mechanism;

Fig. 3 is a plan with parts broken away of the apparatus shown in Fig. 2;

Fig. 4 is a view similar to Fig. 2 but with parts broken away;

Fig. 5 is a section taken along the line V-V of Fig. 4;

Figs. 6, 7, and 8 are diagrammatic views of parts of the mechanism in various positions.

Referring to Fig. l, I show a refrigerator 10, including a cabinet 11, a cooling compartment 12, and an evaporator 13 in heat exchange relation therewith. A motor-compressor unit 14 for circulating refrigerant is preferably mounted on the cabinet 11 and is operatively controlled by a switch 23 (Fig. 4), included in the mechanism 15. The switch 23 closes and opens the electric circuit of the motor compressor unit 14 to initiate and terminate operation of the same. The well-known compression-expansion cycle is used to provide refrigeration within the cabinet 11. Refrigerant vapor is withdrawn from the evaporator 13 by the motor-compressor unit 14 and forced under pressure to a condenser 16 where it is condensed. The condensed refrigerant then passes through an expansion device 1'? to the evaporator where it is vaporized, abstracting heat from the cooling compartment 12 in a wellknown manner. The cycle is repeated so long as the motor-compressor unit 14 operates. A fan 18 may be used to circulate a cooling medium through the condenser to assist in cooling the refrigerant.

The control mechanism 15 includes a base 20 and a cover orhood 21 enclosing a suitable switch, for example, the fluid or mecury switch 23, which is opened and closed due to rocking or tilting movement of a rockable or tiltable member; mechanism operating in response to cooling unit temperature to rock or tilt the tiltable member to open and close the switch; and means, preferably manually operable or settable, to advance or retard closing and opening of the switch in response to movement of the mechanism due to cooling unit temperature.

The mechanism operating in response to cooling unit temperature includes a frame or pedestal 24 secured to the base 20 and consisting preferably of side members 25 and 26 and upper and lower cross members 27 and 28, respectively. A movable member, for example, a lever 29, is pivoted at 30 to the pedestal side member 25 and extends across the space between the side members and beyond the other side member 26. Biasing means, for example, a spring 31, exerts force on the movable member or lever and tends to cause it to move in one direction, and temperature responsive means, for example, the bellows 32, opposes the spring and causes the lever or movable member to move in the other direction against the force of the spring.

The temperature responsive means or bellows 32 has a tube 32a secured thereto, which tube 32a extends within the cooling compartment 12 and is subjected to the temperature of the cooling unit 13. The bellows 32 and tube 32a define a chamber within which a volatile gas is confined.

As the pressure of gas varies with the temperature of the cooling unit 13, the amplitude of the bellows 32 will depend on the pressure of the conlined gas and incidental cooling means temperature.

The outer end of the lever 29 is pivotally connected at 33 to the rockable and tiltable memher 34, which rocks or tilts about the fulcrum 35 to open and close the switch. It will, therefore, be apparent that change in temperature results in motion of the lever 29 and that this brings about tilting or rocking of the tiltable or rockable member 34 to open and close the switch.

The positions assumed by the bellows 32, lever 29, and the switch 23 when the latter is open and closed are shown, respectively, in Figs. 4 and 6.

Preferably, as illustrated, the biasing means or spring 31 is arranged above the lever 29 and in the space between the latter and the upper cross member 27, the upper cross member carrying an adjustable follower 36 for adjusting the tension of the spring.

The bellows 32 is arranged underneath the lever and between the latter and the lower cross member 28 of the pedestal.

By varying the force or compression of the spring, the temperatures at which the switch is closed or opened may be raised or lowered. For

example, if it is desired to set the control mechanism to close the switch at a lower temperature, the spring force isdiminished and vice versa. The spring is adjusted for a normal operating condition and variability is secured by mechanism associated with the rockable or tiltable member 34, serving to advance or to retard opening and'closing of the switch with respect to movement, of the lever 29, and which will now be described. I

The adjustment for securing the ad ance and retard effect of opening and closing of the switch with respect to the operating range of movement of the temperature responsive member includes a longitudinal slot37 provided in the rockable or tiltable member 34 and having the fulcrum pin 35 disposed therein. If the fulcrum pin is lowered, with the lever 29 in a given position, it will be apparent that the rockable member or cradle 34 will be moved angularly in a counter clockwise, or switch-closing, direction about the pivotal connection with the result that both opening and closing of the switch may be secured with lower pressure exerted by the bellows, and, therefore, with maintenance of lower temperature in the refrigerator. On the other hand, as the fulcrum pin 35 is raised, greater upward movement of the lever 29 is required to open and close the switch. with the result that the opening and closing temperatures are proportionately increased. In Fig. 7, the fulcrum pin 35 thereby.

While I have shown my invention in but one form, .it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. The combination with a switch, of a tiltable member having sufficient amplitude of motion to open and close the switch, a lever operatively connected to the tiltable member for tilting the latter, a spring for moving the lever in one direction, means responsive to a change in pressure or temperature for moving the lever in the other direction against the force of the spring, means for adjusting the compression of the spring to advance or retard said amplitude of opening and closing motion relative to the lever, and means providing for varying the ratio of angular movement of the lever with respect to angular movement of the tiltable member.

2. The combination with a switch, of a tiltable member having suilicient amplitude of motion to open and close the switch, a lever movable in response to a change in pressure 'or temperature for tilting the tiltable member, means providing for varying the ratio of angular movement of the tiltable member. to angular movement of the lever, and means providing for angular adjustment of the tiltable member independently of the lever to advance and retard said amplitude of opening and closing motion relative to movement of the lever.

B. The combination with a switch, of a tiltable member for opening and closing the switch, a lever movable in response vto a change in pressure or temperature for tilting the tiltable member, means for singularly adjusting the tiltable member relative to the lever to advance and retard opening and closing of the switch relative to movement of the lever, and means for preventing motion of the lever in the switchclosing direction and closing or" the switch when the adjusting means is fully retarded.

i. The combination with a switch, of a member rockable to open and close the switch and.

' having a longituolinally-entending slot, 21 fulcrum pin fitting the slot, a member movable in respouse to a change in pressure or temperature and operatively connected to said IOCllZQhlG member, and supporting means for the fulcrum pin including a manually-adjustable cam for varying the position. of the pin.

5. The combination with a switch, of a mem ber rockable to open and close the switch and having a longitudinally-extending slot, a fulcrum pin fitting the slot, a member movable in response to change in pressure or temperature and operatively -connected to rocltable member, a lever carrying the fulcrum pin, means for biasing the lever for movement in one direction, and manually-operated adjusting means for moving the lever in the other direction in order that the position or the fulcrum pin may be varied.

6. The combination with a switch, of a member rockable to open and close the switch and having a longitudinal slot, a fulcrum pin fitting the slot, means movable in response to a change in pressure or temperature and operativelyconnected to the, rockable member, a pivoted lever supporting the fulcrum pin, and means for controlling the position of the lever including a spring tending to move the lever in one direction and a manually-operated cam for moving the lever in the other direction against the Iorce of the spring.

7. The combination with a switch, of a mem ber rockable to open and close the switch, fulcrum supporting means for the rockable member and providing for longitudinal movement of the rockable member, a lever having its outer end operatively-connected to the rockable member, means for biasing the lever for movement in one direction, means responsive to a change in pressure or temperature for moving the lever in the opposite direction against the force of the biasing means, and means for adjusting the length of the lever to vary the distance of its connection with the rockable member from the fulcrum supporting means for the latter.

8. The combination with a switch, of a member rockable to open and close the switch and having a longitudinal slot, a fulcrum pin fitting the slot, a member movable in response to a change in pressure or temperature and operatively-connected to the rockable member, means for varying the position of the fulcrum pin in order to advance or retard the amplitude of opening and closing movement of the rockable member with respect to movement of the movable member, and means providing for adjustment of the connnection between the movable and rockable members inwardly and outwardly with re spect to the fulcrum pin.

9. The combination with a switch, of a member rockable to open and close the switch, a pad estal including top and side portions, a lever piv itally-connected to one side portion and entending across the space between the side portions and beyond the other side portion, the outer end of said lever being operatively-connected to said roclrable' member, biasing means disposed in said space at one side of the lever, e: ansible in said space at the other side of lever and re sponsive to a change in pressure or mperature, a. bracket carried by said pedesta it" true, and means for adjusting the roclcable member gularly with respect to the lever so as to advance or retard the amplitude of switchmpening closing movement with to movement of the lever and including a manuallyop rated element carried by bracket.

10. The combination with a switch, of a switch operating member having a sufficient amplitude of movement to open and close the switch, a ber movable in response to a change in pressure or temperature and operatively-connected to the switch-operating member, means for adjusting the switch-operating member so as to advance or retard its amplitude of opening and closing movement with respect to movement of the movable member, and adjustable me ns for pre venting movement of said vable iber in the A I. l s

direction of increasing pressure or temperature and closing of the switch when the adjusting means are in full retarded position.

11. In an automatically and manually operated control mechanism for a refrigerating system, the combination of a switch for initiating and terminating operation of the system, a fulcrum for the switch, means responsive to temperature for opening and closing said switch to maintain the system between predetermined high and low temperatures, means for adjusting said last-named means so that both the opening and closing temperatures may be raised or lowered to provide for adjustment of the temperature-responsive means suitable for the system, a second adjusting means for varying the difference between the opening and closing temperatures, and means for moving said fulcrum to raise or lower both the opening and closing temperatures;v said last-mentioned means having a plurality of positions wherein said system is automatically maintained for operation over a range of predetermined high and low temperatures and positions wherein the temperature responsive element is inefiective to 0perate said switch.

12. In an automatically and manually operated control mechanism for a refrigerating system, the combination of a switch for initiating and terminating operation of the system, a fulcrum for the switch, a temperature-=responsive element for opening and closing said switch to maintain the system between predetermined'high and low temperatures, a member interposed between said element and said switch for transmitting movement of the former to the latter, means for adjusting said element to change in a single direction the predetermined high and low temperatures, means carried by said member for changing one of said predetermined temperatures, and means for moving said fulcrum relative to said member to change in a single direction the predetermined high and low temperatures; said last-mentioned means having a plurality of positions wherein said system is automatically maintained between predetermined high and low temperatures and positions wherein the temperature responsive element is ineffective to 0perate said switch.

JOHN J. BAUMAN. 

